Energy generation and storage have long been a subject of study and development. Of special significance is the storage of electrical energy in a compact form that can be easily charged and discharged, such as a rechargeable battery and/or electrochemical capacitor. High power, especially high current pulse rechargeable electrochemical storage devices are required in applications using electrical pulse, such as two-way communications, power tools, and laptop computers to name but a few. In these devices, high electrochemical kinetic rate, long cycle life of the electrodes, and good ionic conductivity of the electrolyte are extremely important features. In addition, small size of electrical components has become a highly valued feature because of the drive toward miniaturization of circuits in portable devices.
Where an energy storage device is needed with excellent power burst capabilities and rapid electrical response, electrolytic capacitors have been favorite choices for circuit design engineers. However, although their performance characteristics have secured them a prominent place in electrical circuits, the capacitance of these capacitors is relatively small, thus high-capacitance electrolytic capacitors are undesirably large in size.
Accordingly, there exists a need for capacitors with many of the same performance characteristics of electrolytic capacitors, but with improved energy density.